{Extract}
° Date and version of current assessment: 14 August 2026, v4
Risk statement
Since first detected in May 2026, the Bundibugyo virus disease (BVD) outbreak has rapidly evolved into a large and geographically expanding epidemic in the Democratic Republic of the Congo, with sustained transmission, high mortality and an increasing risk of further international spread. The current outbreak is the second documented Bundibugyo virus disease outbreak in the country, after the 2012 outbreak, the largest Ebola disease outbreak ever recorded in the Democratic Republic of the Congo, irrespective of Ebola virus species.
Following laboratory confirmation of Bundibugyo virus on 15 May 2026, with 13 laboratory-confirmed cases from 20 tested specimens, retrospective investigations conducted by the provincial field team identified 246 suspected cases and 65 deaths (CFR: 26.4%) across three health zones in Ituri (Mongbwalu, Rwampara and Bunia) occurring between 15 April and 13 May 2026.
By 13 August 2026, the outbreak had spread to six of the country’s 26 provinces (Bas-Uélé, Haut-Uélé, Ituri, North Kivu, South Kivu and Tshopo) encompassing 54 health zones, with 4566 laboratory-confirmed cases and 2128 deaths (see map in the Annex).
Since the beginning of the outbreak, 155 healthcare workers have been infected.
Positively, 918 patients have recovered and been discharged from treatment centres. These figures demonstrate a substantial increase in the scale and geographic extent of the outbreak over the past three months.
Ituri Province remains the epicentre of the outbreak, accounting for 3912 confirmed cases (86%) and 1701 deaths (80%) as of 13 August. The outbreak was initially detected as a cluster in Mongbwalu Health Zone, a rural gold-mining area characterised by high population mobility linked to mining, trade and movement between communities.
Spread to additional health zones within Ituri and subsequently to other provinces occurred with population movement and connections between affected communities.
Healthcare facilities also contributed to the establishment of new transmission chains, with Bas-Uélé being identified as the most recently affected province on 12 August. This geographic spread has increased the complexity of the response, requiring sustained surveillance, contact tracing and infection prevention and control measures across an increasing number of affected areas.
Ituri Province also has strong cross-border connectivity with Uganda and South Sudan, highlighting the continued risk of exportation.
The crude case fatality ratio (CFR) to date is 47%, underscoring the severity of the outbreak and ongoing challenges related to timely case detection, access to and quality of clinical care, and effective interruption of viral transmission.
Delays in recognising cases increase the likelihood of onward transmission within households, communities and healthcare facilities.
Contact tracing and follow-up have increased significantly since the start of the outbreak, but documentation and registration remain incomplete, limiting data accuracy.
As of 13 August, 18811 contacts had been identified and documented in a line list with detailed contact information, while the number of contacts reported as being under follow-up is significantly higher, but many contacts lack detailed information. This limits the ability to fully assess epidemiological links, exposure histories and transmission patterns among all contacts under follow-up and indicate gaps in contact investigation and documentation.
The outbreak has also demonstrated a clear potential for cross-border spread. The first international spread was identified in Uganda in May 2026, when a symptomatic patient from the Democratic Republic of the Congo travelled to Kampala and was subsequently confirmed with Bundibugyo virus disease.
Additional cases were subsequently identified in Uganda, demonstrating that population movement across the border can result in onward local transmission.
In response to the expanding outbreak and increasing risk of international spread, on the 17 May 2026, the WHO Director-General determined the outbreak in the Democratic Republic of the Congo and Uganda a public health emergency of international concern (PHEIC).
On 22 May, an International Health Regulation (IHR) Emergency Committee was convened. Considering the advice of the IHR Emergency Committee, The Director-General of WHO issued temporary recommendations to all States Parties, including to strengthen surveillance, preparedness and response in countries with documented BVD, and those sharing land borders with affected countriesat highest risk of importation.
Since the start of the outbreak and as of 13 August, cases have been detected and/or treated outside of the Democratic Republic of Congo. Uganda reported 20 confirmed BVD cases during the outbreak (from 15 May 2026).
The last imported case was reported on 21 June and discharged on 16 July; the 42-day enhanced monitoring period, as per international guidance, will therefore finish on 27 August. All 836 identified contacts completed the required 21-day follow-up period; during this period, six contacts, including four healthcare workers, developed BVD and were treated.
France reported a single imported BVD case on 24 June 2026, with no secondary transmission. The case was discharged on 4 July, and all five identified flight contacts completed the required 21-day follow-up period without developing symptoms. The 42-day enhanced monitoring period comes to an end on 15 August.
Germany reported two BVD cases diagnosed in the Democratic Republic of the Congo and subsequently medically evacuated to Germany for treatment. Both patients recovered and were discharged on 6 June and 28 July, respectively.
The cases were managed under strict infection prevention and control measures, and no secondary transmission was reported, therefore, no contacts were identified.
Although these events demonstrate that imported cases can be detected and transmission interrupted, the continuing intensity of transmission in the Democratic Republic of the Congo means that the risk of further exportation remains.
Entry and exit health screening and surveillance measures are in place at airports, ports and official land border crossings; however, movement through informal border crossing routes may occur, presenting an ongoing risk of virus exportation, importation and onward transmission.
Countries sharing land borders with the Democratic Republic of the Congo remain at risk because of frequent crossborder population movement. Uganda, the Central African Republic and South Sudan are of particular concern for importation given their proximity, high population mobility and connectivity with areas of the Democratic Republic of the Congo currently experiencing intense transmission.
For the Central African Republic and South Sudan, these risks are further compounded by high humanitarian needs, population displacement, insecurity and underlying limitations in health-system capacity.
The risk in the Democratic Republic of the Congo remains assessed as very high, reflecting the current intensity and breadth of the outbreak, sustained transmission across multiple provinces and health zones, and the continued presence of epidemiological and operational factors that facilitate further transmission.
The main considerations supporting this assessment are:
• The outbreak has increased substantially since the previous risk assessment. As of 6 June 2026, 515 confirmed cases and 91 confirmed deaths had been reported in the Democratic Republic of the Congo. By 13 August 2026, the number of cumulative confirmed cases had increased nearly nine-fold, from 515 to 4566, while the number of cumulative deaths had increased more than twenty-three-fold, from 91 to 2128. The CFR increased from 18% on 6 June to 47% on 13 August. Although the CFR reported on 6 June was noted at the time to likely be an underestimate of the true fatality ratio, the substantial increase in the CFR nevertheless highlights the severity of the outbreak and continued challenges in timely detection, referral and clinical management of cases.
• The reported CFR may increase further as additional deaths are investigated and outcomes are established More than 100 probable deaths that occurred before the outbreak was declared have been investigated and are awaiting Ministry of Health (MoH) validation; this inclusion could increase the reported CFR. Additionally, as of 10 August, more than 700 confirmed cases had no final outcome, excluding reported deaths, recoveries, and patients in designated isolation centres. This incomplete outcome ascertainment should be considered when interpreting the current CFR.
• The geographic extent of the outbreak has expanded considerably since the previous risk assessment. The number of affected health zones has increased from 25 to 54 (116%) with transmission now reported across five provinces, compared with three provinces on 6 June.
• Ituri has the highest number of affected health zones, (28/36), followed by North Kivu (12/34), Haut-Uélé (6/13), Tshopo (6/23), South Kivu (1/34), and Bas-Uélé ( 1/11), confirming the continued geographic spread of the disease. Furthermore, 45 of the 54 affected health zones have reported confirmed cases within the past 21 days, indicating ongoing active transmission across a large geographic area.
• Ituri remains the principal focus of transmission and shows substantial evidence of ongoing, undetected transmission. The province, which borders both Uganda and South Sudan, accounts for 86% (3912/ 4566) confirmed cases and 80% (1701/ 2128) reported deaths in the Democratic Republic of Congo. Transmission continues in both densely populated urban areas and rural settings. More than 80% of new infections in the province are detected outside known contact lists, indicating that many transmission chains remain unidentified, while retrospective investigation indicates that approximately 40% of new cases have a known epidemiological link to a previous case. Approximately two-thirds of deaths occur outside designated Ebola Treatment Centres (ETCs), suggesting delayed healthcare-seeking, late detection and continued community transmission. Although safe and dignified burial (SDB) teams are being scaled up, gaps remain in alert management, notification and investigation of deaths, systematic swabbing, contact identification and tracing, decontamination and timely implementation of SDB measures. The continued intensity of transmission in Ituri, together with its proximity to international borders and spread to additional provinces, increases the potential for further transmission within the Democratic Republic of the Congo and across borders.
• Transmission among healthcare workers and capacity constraints in health-care settings remain a concern. The number of confirmed infections among healthcare workers increased nearly tenfold since 6 June, from 16 to 155, including 45 deaths. This continued occurrence of infections highlights possible occupational exposure risks and gaps in infection prevention and control (IPC) implementation in healthcare facilities, which may contribute to further transmission. However, good-quality data are not currently available to determine whether exposures occurred during healthcare duties or in community settings, as only eight of the 54 affected health zones have received training to conduct surveillance activities, including detailed case investigations. At the same time, limited health-care infrastructure, insufficient Ebola treatment and isolation capacity, and inadequate ambulance availability constrain timely isolation, referral and clinical management of suspected and confirmed cases. These gaps may increase the risk of health-care-associated transmission and delayed access to care, while contributing to frustration among affected families, undermining community confidence in the response and potentially delaying care-seeking.
• Contact tracing and follow-up have increased substantially but available documentation remains incomplete. Although contact tracing activities have expanded substantially, more than 80% of newly reported infections continue to be detected outside known contact lists, indicating that many transmission chains remain unidentified. As of 12 August, 18811 contacts had been identified and documented with detailed information. However, the number reported as under follow-up is considerably higher, with complete line-list data not yet available for all contacts. This limits assessment of epidemiological links, exposure histories and transmission patterns. The scale of contact tracing needed, insufficient human resources, ongoing strikes among MoH responders and community health workers, and persistent pockets of community mistrust and population movement continue to challenge timely and complete contact tracing.
• Ongoing conflict and insecurity in Ituri and North Kivu provinces continue to constrain response operations. Insecurity restricts the movement of surveillance and Rapid Response Teams, limits the secure transport of laboratory specimens, and hinders contact tracing, SDB activities and community engagement. These access constraints may delay detection and investigation of cases and deaths and limit the timely implementation of response measures. In addition, insecurity may discourage individuals from seeking healthcare.
• Laboratory capacity and testing supply constraints continue to affect timely confirmation and response. Delays in sample transportation and, in some locations, communication of laboratory test results can delay confirmation, affect timely isolation, clinical management, contact identification and implementation of other public health measures, while also contributing to community frustration.
• No licensed vaccine or specific antiviral treatment is currently available for Bundibugyo virus disease. Although a randomized clinical trial for Ervebo is currently being initiated as well as the PARTNERS trial for effective treatments, the response currently relies on community engagement and early detection and isolation of all cases, intensive supportive clinical care, infection prevention and control, contact tracing, safe and dignified burials, and other public health and social measures, placing substantial operational demands on the response.
• Community protection and engagement capacities have been strengthened but remain insufficient relative to the scale of the outbreak. More targeted and in-depth engagement of local leadership, trusted local networks, training of community health workers (CHWs) and establishment of community brigades in hightransmission areas have strengthened community-level response capacity. Efforts to provide at-risk communities with timely and accurate information have also increased. However, available resources and capacity remain inadequate relative to the increasing scale of the outbreak compounded by persistent community mistrust and delays in scaling up essential response services, contributing to delays in referral and care-seeking, underreporting and reduced uptake of response measures.
• Funding gaps threaten the continuity and scale of the response. Insufficient and unpredictable funding limit the ability to sustain essential surveillance, laboratory, clinical care, infection prevention and control, contact tracing, community engagement and other response activities, particularly in areas affected by insecurity and limited access.
• The potential for national spread remains significant. The outbreak has expanded across six provinces and 54 health zones, including Kisangani, a major port city on the Congo River and a key link to the capital, Kinshasa. Sustained transmission, extensive population movement and major transport and trade routes linking affected and unaffected areas increase the likelihood of further geographic expansion within the Democratic Republic of the Congo.
The risk for countries sharing land borders with the Democratic Republic of the Congo remains assessed as high, reflecting the ongoing transmission and geographic expansion of the outbreak, and particularly for countries with sustained cross-border population movement and close social and economic links with affected areas.
The key factors supporting this assessment include:
• High population mobility across formal and informal routes. Cross- border movement associated with trade, mining, pastoral activities, family visits, seeking health care, displacement and insecurity remain frequent across the region. Movement through both official and informal crossing points, particularly between border communities and affected areas, creates opportunities for infected individuals to cross borders before detection.
• Risk of undetected importation and onward transmission. The high proportion of infections identified outside known contact lists indicates that transmission chains remain undetected in affected communities. Cases or contacts crossing international borders or being lost to follow-up may therefore result in delayed detection and onward transmission in neighbouring countries. Cross-border movement to access health services may be particularly relevant where health-care capacity is limited in affected areas of the Democratic Republic of the Congo.
• Variable surveillance, preparedness and response capacities. Differences in BVD surveillance and case detection, sample transportation and laboratory capacity, clinical management, infection prevention and control, contact tracing and outbreak response capabilities across neighbouring countries may affect their ability to rapidly identify and contain imported cases.
• Operational, humanitarian and access constraints may hinder preparedness and response. Insecurity, population displacement, limited access to health services and challenging operating environments in border areas may constrain surveillance, contact tracing, laboratory investigation, community engagements, and other preparedness and response activities in neighbouring countries.
• Gaps in cross-border information sharing and community preparedness may delay detection and response. Delays in sharing information on cases and contacts who cross borders, including through IHR mechanisms and direct coordination between WHO and partner response teams, may hinder timely follow-up. Limited resources and uneven capacitiesto train, equip and support CHWsfor community-based surveillance and RCCE, generate and use timely community evidence and engage trusted local leaders and community networks may further delay care-seeking and detection and constrain rapid response following an imported case.
The risk for the rest of the African Region and at the global level remains assessed as low, based on the available epidemiological evidence and the absence of widespread or sustained transmission beyond the main affected areas.
The key considerations supporting this assessment include:
• Transmission remains concentrated in the Democratic Republic of the Congo. The majority of reported cases and deaths remain concentrated in the Democratic Republic of the Congo, however, transmission has also been documented in Uganda, and a travel-associated case was detected in France. These events demonstrate that the virus can cross international borders through population movement and underscore the importance of strengthened surveillance, early detection, laboratory capacity, infection prevention and control, and response readiness in countries with epidemiological and population-mobility links to affected areas. Accordingly, regional and global preparedness has been increased.
• There is currently no evidence of sustained transmission beyond the Democratic Republic of the Congo. The continued outbreak in the Democratic Republic of the Congo presents a risk of further exportation, particularly to countries with strong population and travel links, but available evidence does not indicate ongoing international transmission.
• International exportation remains possible. Individuals infected in the Democratic Republic of the Congo may travel during the incubation period before symptoms develop, and cases could therefore be detected in other countries. However, in the absence of evidence of sustained transmission outside the affected areas both in this outbreak and historically in previous Ebola outbreaks, this possibility does not currently warrant an increase in the overall regional or global risk assessment. Despite the risk of wider regional and global spread remaining limited, continued vigilance is required for surveillance, rapid detection and investigation of suspected cases, and appropriate preparedness in countries with travel and population links to the Democratic Republic of the Congo to ensure that any exported cases are promptly identified and contained.
{1} Confidence refers to the level of confidence in the data/information or the quality of the evidence available at the time the RRA is conducted. Poor quality information may increase the overall perceived risk due to the incertitude in the assessment.
Source:
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